Summary A Helijet International Incorporated (Helijet) SikorskyS-76A helicopter (registrationC-GHJL) was on an IFR (instrument flight rules) med-evac flight from Victoria, British Columbia, to Vancouver Harbour. The crew was in communication with the Victoria terminal controller who, at approximately 1315 Pacific daylight time, cleared the helicopter to descend from 3000to 2200feet in the vicinity of Active Pass. Shortly thereafter, the controller alerted the crew that an opposite-direction radar target was one nautical mile (nm) ahead. It had been previously undetected by the controller. The crew immediately spotted an aircraft landing light directly ahead and took evasive action to the right. The opposing traffic was a Harbour Air Ltd. (Harbour Air) deHavillandDHC-3 (Otter), registration C-FRNO, on a VFR (visual flight rules) flight from Vancouver Harbour to Victoria Harbour. The pilot had just established contact with the Victoria tower outer airport controller and, as he was levelling at 2500feet above sea level (asl) approximately one nautical mile (nm) north of Active Pass, was cleared through the Victoria Airport control zone. Although the pilot was not advised of any conflicting traffic, he spotted the helicopter, C-GHJL, at his 12o'clock position less than one nm, in an evasive manoeuver. The Otter did not take any evasive action. Radar data displayed both aircraft passing approximately two nm south of the Active Pass NDB (non-directional [radio] beacon) at 2700feet with less than 600feet lateral spacing. Ce rapport est galement disponible en franais. Other Factual Information History of Flight The helicopter was operating within ClassC airspace along a company area navigation (RNAV) route. This route is not published on aeronautical charts, but crosses a published southbound VFR route approximately two nm south of the Active PassNDB. The helicopter had commenced descent when it was approximately three nm south of the Active PassNDB, with the intention of cancelling IFR, when able, and following the low-level transit route to Vancouver Harbour. The helicopter did not have a landing light on for cruise flight because of the downward orientation of the light. Figure1. Diagram of airspace and aircraft tracks (based upon radar data) Because of the reduced ceilings and visibilities around Vancouver, the Otter aircraft had remained at 700feet above ground level (agl) within ClassG airspace below the Vancouver tower outer control zone. The weather improved once the Otter was clear of this zone, which permitted the aircraft to climb to 2500feet while proceeding within ClassE airspace along a published, low-level transit route toward Active Pass. In accordance with VFR, the pilot was required by Canadian Aviation Regulations (CARs) 602.21 to maintain an altitude at least 500feet below the cloud base and to maintain separation from other aircraft. Radar data show that the Otter climbed as high as 2800feet and entered Victoria terminal airspace (ClassC) while still outside the lateral boundary of Victoria tower airspace. (SeeFigure1.) The Otter was flying with pulse lights on. Weather The 1300 Pacific daylight time1 weather report for the Vancouver International Airport was as follows: a very light easterly breeze, four statute miles (sm) visibility in light rain and mist, scattered cloud at 500feet agl, and a broken ceiling at 1600 feet agl. The 1300 weather observation for the Victoria International Airport was as follows: a light southeasterly breeze, seven sm visibility in light rain and mist, several levels of cloud reported as few, and a broken ceiling at 6100feet agl. There are no official reporting stations between Vancouver and Victoria. However, pilots using the route described the northbound visibility to be a grey, murky haze. The southbound visibility faced improving conditions; the Victoria Airport could be seen from Active Pass, approximately 13nm away. The helicopter had just broken out of cloud, and at approximately 2800feet asl, enough forward visibility was established for the crew to spot the landing light ahead of them. Classification of Airspace Canadian Domestic Airspace has seven classifications. The classification of airspace determines the operating rules, the level of air traffic control (ATC) service provided within the structure, and in some instances, communications and equipment requirements (Designated Airspace Handbook TPE1820E). The Vancouver Terminal Control Area (TCA) covers most of the southern Straight of Georgia and is designated as ClassE transition2 airspace from 700feet asl up to and including 2500feet asl. Airspace is designated ClassE when an operational need exists for controlled airspace, but it does not meet the requirements of ClassA, B, C, orD.3 Above 2500feet lies Victoria terminal ClassC airspace up to 12500feet. Both Vancouver and Victoria airports have an outer control zone designated as ClassC airspace from 1200feet asl up to and including 2500feet asl to a range of 12nm from the respective airport. There is approximately 10nm of ClassE airspace between these control zones. When operating under VFR in level cruising flight at or below 3000feet agl, pilots are not required to maintain altitude appropriate for the direction of flight.4 Class E airspace is controlled airspace; however, ATC control applies only to IFR flights. VFR flight is permitted to operate within ClassE airspace without any special requirements other than compliance with weather minimums applicable to controlled airspace. ClassC airspace is controlled airspace within which VFR and IFR flights are permitted, but VFR flights require an ATC clearance to enter. Within ClassC airspace, controllers are required to provide conflict resolution between IFR and VFR aircraft, and traffic information to VFR flights. It is left to the controller's judgement to determine when traffic may be a conflict.5 Transponders are required within ClassC airspace, but are not required within basic ClassE airspace. Air Traffic Control The Otter was equipped with an altitude encoding transponder, and the pilot was still using the code assigned by ATC on departure from Vancouver Harbour. However, radar service terminated when the Otter left the Vancouver Harbour control zone and proceeded en route within ClassG orE airspace. The present position symbol (PPS) displayed on both the Victoria terminal NARDS (NAV CANADA Auxiliary Radar Display System) monitor and the Victoria tower controllers' NARDS monitor, had an attached data tag that included at least the transponder code, aircraft altitude, flight number, and controller jurisdiction code. The NARDS monitor is the primary display for the Victoria tower outer control position. The NARDS monitor at the Victoria terminal position is a secondary display monitor. On the RSIT (Radar Situation Display) monitor, the Otter appeared as an unknown target (asterisk with a two digit altitude indicator) commonly referred to as a splat. When a non-radar identified flight makes initial contact, a controller will verbally confirm the transponder altitude readout and inform the crew when the flight is radar identified. The pilot was not informed that the flight was radar identified, but did receive a clearance to enter and transit through the Victoria tower ClassC airspace at 2500feet. The helicopter and the Otter were not coordinated as traffic between the Victoria tower and Victoria terminal controller because, in accordance with an inter-unit agreement, it was not required to be. The agreement describes a 500-foot buffer zone within the Victoria terminal ClassC airspace overlying the Victoria tower ClassC airspace. It directs that, without coordination, the Victoria terminal controller may clear traffic over the Victoria tower ClassC airspace at or above 3000feet, and the Victoria tower controller may clear traffic to maintain 2500feet or below within the tower's ClassC airspace. If either controller wishes to clear an aircraft through the buffer zone between 2500feet and 3000feet, coordination would be required. The Victoria terminal controller was responsible for five IFR aircraft (including one training flight), one VFR aircraft, and was planning for two pending IFR departures within the eight-minute period since assuming the control position. Staffing of the Vancouver West specialty consisted of four controllers plus one supervisor; two were on a break and one was filling a data position shared between the Victoria sector controller and the Abbotsford sector controller. At the time of the incident, the data person was busy in the Abbotsford sector and was unable to assist the Victoria terminal controller. The staffing level was consistent with the stated minimum staffing level for the specialty. Approximately eight minutes after a controller shift change, the relieving Victoria terminal controller cleared the helicopter to descend to 2200feet, the minimum en route altitude. The controller was executing a traffic sequencing plan for flights proceeding to Vancouver and issued the descent clearance to the helicopter to make the 3000-foot altitude available for the descent of another aircraft in accordance with the plan. Separation between IFR and VFR consists of preventing the PPSs from overlapping or providing at least 500feet of vertical separation unless visual contact by at least one crew is established.6 Radar scanning is the basic skill employed by controllers to ensure radar separation between aircraft. It was incumbent upon the controller to verify whether conflicting traffic existed before issuing a descent clearance to the IFR helicopter. Flight progress strips aid scanning by providing a physical organization and record-keeping list of aircraft for which the controller is responsible. The controller did not have a flight progress strip for the Otter because it was not operating on a flight plan that proposed entering the controller's airspace jurisdiction. Aids to Visual Detection The AIP, Section RAC (Rules of the Air and Air Traffic Services)2.5.1, Use of Controlled Airspace by VFR Flights, states: because of air traffic density at certain locations, the 'see and be seen' principle [see-and-avoid principle] of VFR separation cannot always provide positive separation. Further, Section AIR (Airmanship)3.7, Vision, notes that good visual scanning practices are required for the see-and-avoid principle to be effective. Pilots need to identify conflicting traffic while there is still time to take avoiding action. Research by the Australian Bureau of Air Safety Investigation concluded the see-and-avoid principle in the absence of traffic alerts is subject to serious limitations and that un-alerted see-and-avoid has a limited place as a last resort means of traffic separation at low closing speeds.7 Research conducted by the MIT Lincoln Laboratory during traffic alert and collision avoidance system (TCAS) flight testing showed a 50percent improvement in the visual target acquisition rate by pilots alerted to the presence of other aircraft, and a 40percent improvement in the median range of visual acquisition.8 TSB Engineering Report LP86/95 indicated that visual search effectiveness improves by an approximately eight-fold factor when TCAS equipment is used (that is, one second of search with the aid of a TCAS traffic advisory is as effective as eight seconds of un-alerted search). Supporting Information This occurrence is the fifth reported air proximity event recorded in the TSB database within the last 12months involving an IFR versus VFR conflict within ClassC andE airspace lying within the bounds of a line connecting Victoria, Bellingham, Abbotsford, Vancouver, and Nanaimo airports. There were a number of similarities between the four previous occurrences. In all four, there was a risk of collision, and the VFR aircraft was not radar identified nor was there any communication with it. In three cases no traffic information was passed by the controller. In two cases traffic was spotted by the IFR crew, but not in time to prevent a risk of collision. A risk management study conducted by Transport Canada in2003 found that over two million passengers are transported each year (many by floatplane or helicopter) in the area over the southern Strait of Georgia between Vancouver, Victoria, and Nanaimo. Twenty four risk of collision scenarios were identified. One of the hazards identified was that IFR routes transit ClassE airspace without traffic protection from general aviation aircraft. Risk-of-collision scenario#21 describes a VFR aircraft, climbing from ClassE airspace to ClassC airspace, conflicts with an IFR aircraft descending to ClassG airspace while both are transiting the boundary of two TCAs. One recommendation of the study was a review of IFR routes in the Vancouver TCA to improve airspace protection for IFR flights transiting ClassE airspace. An airspace study entitled Airspace Review of the Vancouver, Lower Mainland and Victoria Areas was initiated by NAV CANADA on 26November2003. The purpose of the study is to determine the optimum airspace configuration, routes, and procedures required for the area. The projected completion date is autumn2005.